TTUHSC School of Medicine
HomeSchool of MedicineCell Physiology and Molecular BiophysicsFaculty

Cell Physiology and Molecular Biophysics

  Photograph of Dr. Guan    

Lan Guan, M.D., Ph.D.

Associate Professor

Cell Physiology and Molecular Biophysics

Ph.D.,Tokai University School of Medicine,Isehara, Japan, 2000
M.D.,Chongqing Medical University,Chongqing, China, 1984

  Department of Cell Physiology and Molecular Biophysics
  Center for Membrane Protein Research
  Texas Tech University Health Sciences Center
  3601 4th Street, STOP 6551
  Lubbock, Texas 79430
  Office Phone: (806) 743-3102
  Office room: 5A163
  FAX: (806) 743-1512
  E-mail: Lan.Guan@ttuhsc.edu



Research Interests

Membrane proteins constitute ~30% of all eukaryotic proteins and play crucial roles in many aspects of cell function. The long-term goal of our research is to understand the mechanism of solute/cation symport. Currently, we are studying bacterial melibiose permease (MelB), a model system, to understand Na+/sugar symport by utilizing an integrated approach, including X-ray crystallography, genetic engineering, and biochemical & biophysical analyses. We are also developing novel techniques for discovery of protein-capture reagents that, like an antibody, bind to a target protein and modulate its function.

Current Publication List

Research Articles

[32] Ethayathulla, AS, Yousef, MS, Amin, A, Leblanc, G, Kaback, HR, and Guan, L. (2014) Structure-based mechanism for Na(+)/melibiose symport by MelB. Nat Commun 5, 3009. PMID: 24389923

>>Download PDF File

[31] Chae, PS, Kruse, AC, Gotfryd, K, Rana, RR, Cho, KH, Rasmussen, SG, Bae, HE, Chandra, R, Gether, U, Guan, L, Kobilka, BK, Loland, CJ, Byrne, B, and Gellman, SH. (2013) Novel Tripod Amphiphiles for Membrane Protein Analysis. Chem Eur J 19(46):15645-15651. PMID: 24123610

>>Download PDF File

[30] Jakkula, S. V. and Guan, L. (2012) Reduced Na+ affinity increases turnover of MelBst. J. Bac. 194(20):5538-44. PMID: 22865849

>>Download PDF File

[29] Chae, P. S., Rasmussen, S. G. F., Rana, R. R., Gotfryd, K. G., Kruse, A. C., Manglik, A., Cho, K. H., Nurva, S., Gether, U., Guan, L., Loland, C. J., Byrne, B., Kobilka, B. K., and Gellman, S. H. (2012) A new class of amphiphiles bearing rigid hydrophobic groups for solubilization and stabilization of membrane proteins. Chem Eur J. 18(31):9485-90. PMID:22730191

>>Download PDF File

[28] Guan, L., Jakkula, S. V., Hodkoff, A. A., and Su, Y. (2012) Role of Gly117 in the cation/melibiose symport of MelB of Salmonella typhimurium. Biochemistry. 51(13):2950-7. PMCID: PMC3334291

>>Download PDF File 

[27] Jiang, X., Guan, L., Zhou, Y., Hong, W. X., Zhang, Q., and Kaback, H. R. (2012) Evidence for an intermediate conformational state of LacY. Proc Natl Acad Sci USA. 109(12):E698-704. PMCID: PMC3311394

>>Download PDF File

[26] Zhou, Y., Madej, M. G., Guan, L., Nie, Y., and Kaback, H. R. (2011) An early event in the transport mechanism of LacY: Interaction between helices V and I. J Biol Chem. 286(35):30415-22. PMCID: PMC3162401

>>Download PDF File

[25] Chaptal, V, Kwon, S, Sawaya, MR, Guan, L, Kaback, HR, and Abramson, J (2011). Crystal structure of lactose permease in complex with an affinity inactivator yields new insight into sugar recognition. Proc Natl Acad Sci U S A. 108(23):9361-6. PMID: 21593407

>>Download PDF File

[24] Kudugunti, SK, Thorsheim, H, Yousef, MS, Guan, L, and Moridani, MY (2011).  The metabolic bioactivation of caffeic acid phenethyl ester mediated by tyrosinase selectively inhibits glutathione S-transferase. Chem Biol Interact. 192(3):243-56. PMID: 21458432

>>Download PDF File

[23] Guan, L., Nurva, S., and Ankeshwarapu, S. P. (2011) Mechanism of melibiose/cation symport of the melibiose permease of Salmonella typhimurium. J Biol Chem. 286:6367-74 PMID: 21148559

>>Download PDF File

[22] Chae, P. S., Rasmussen S. G. F., Rana, R., Gotfryd, K., Chandra, R., Goren, M. A., Kruse, A. C., Nurva, S., Loland, C. C., Pierre, Y., Drew, D., Popot, J. L., Picot, D., Fox, B. G., Guan, L., Gether, U., Byrne, B., Kobilka, B., and Gellman, S. H. (2010).  Maltose–neopentyl glycol (MNG) amphiphiles for solubilization, stabilization, and crystallization of membrane proteins.  Nature Methods 7(12):1003-8. PMID: 21037590

>>Download PDF File

[21] Guan, L. and Kaback, H. R. (2009). Properties of a LacY efflux mutant. Biochemistry 48(39):9250-5. PMCID: PMC2754601

>>Download PDF File

[20] Yousef, M. S. & Guan, L. (2009). A 3-D structure model of the melibiose permease of Escherichia coli represents a distinctive fold for Na+ symporters. Proc Natl Acad Sci U S A. 106:15291-6. PMCID: PMC2729278

>>Download PDF File

[19] Zhou, Y. G., Guan, L., Freites, J. A., and Kaback, H. R. (2008). Opening and closing of the periplasmic gate in lactose permease. Proc Natl Acad Sci U S A, 105 (10):3774-3778. PMCID: PMC2268789

>>Download PDF File

[18] Guan, L., Mirza, O., Verner, G., Iwata, S, and Kaback, H. R. (2007) Structural determination of the wild-type lactose permease. Proc Natl Acad Sci U S A, 104 (39):15294-8. PMCID: PMC2000551

>>Download PDF File

[17] Guan, L. & Kaback, H. R. (2007). Site-directed alkylation of cysteine to test solvent accessibility of membrane proteins. Nature protocol, 2, 2012 -7. PMCID: PMC2775809

>>Download PDF File

[16] Orsolya, K.*, Guan, L.*, Szepessy, E., Kukor, Z., Tóth, M., and Sahin-Tóth, M. (2006).  Expression of human cationic trypsinogen with an authentic N terminus using inteinmediated splicing in aminopeptidase P (pepP) deficient Escherichia coli. Protein Expr Purif., 48(1):104-11 (*equal contribution). PMCID: PMC1604731

>>Download PDF File

[15] Mirza, O.*, Guan, L.*, Verner, G., Iwata, S., and Kaback, H. R. (2006). Structural evidence for sugar recognition and mechanism for galactoside/H+ symport in the lactose permease. EMBO J, 25:1177-83 (*equal contribution). PMCID: PMC1422171

>>Download PDF File

[14] Guan, L., Smirnova, I., Verner, G., Nagamoni, S., and Kaback, H. R. (2006). Manipulating phospholipids for crystallization of a membrane transport protein. Proc Natl Acad Sci U S A, 103 (6):1723-1726. PMCID: PMC1413674

>>Download PDF File

[13] Guan, L. and Kaback, H. R. (2004). Binding affinity of lactose permease is not altered by the H+ electrochemical gradient.  Proc Natl Acad Sci U S A, 101 (33):12148-52. PMCID: PMC514448

>>Download PDF File

[12] Vázquez-Ibar, J. L., Guan, L., Weinglass, A. B., Verner, G., Gordillo, R., and Kaback, H. R. (2004). Sugar recognition by the lactose permease of Escherichia coli. J Biol Chem, 19;279(47):49214-21. PMID: 15364943

>>Download PDF File

[11] Vázquez-Ibar, J. L.*, Guan, L.*, Svrakic, M., and Kaback, H. R. (2003). Exploiting luminescence spectroscopy to elucidate the interaction between sugar and a tryptophan residue in the lactose permease of Escherichia coli.  Proc Natl Acad Sci U S A, 100 (22):12706-11 (*equal contribution). PMCID: PMC240682

>>Download PDF File

[10] Ermolova, N., Guan, L., and Kaback, H. R. (2003). Intermolecular thiol cross-linking via loops in the lactose permease of Escherichia coli.  Submitted to Proc Natl Acad Sci U S A, 100 (18):10187-92. PMCID: PMC193537

>>Download PDF File

[9] Guan, L., Sahin-Toth, M., Kalai, T., Hideg, K., and Kaback, H. R. (2003). Probing the mechanism of a membrane transport protein with affinity inactivators. J Biol Chem, 278(12):10541-8 (cover of JBC). PMID: 12471022

>>Download PDF File

[8] Guan, L., Hu, Y.L., and Kaback, H. R. (2003). Aromatic stacking in sugar binding site of lactose permease in Escherichia coli. Biochemistry, 42(6):1377-82, (accelerated publication). PMID: 12578349

>>Download PDF File

[7] Sorgen, P. L., Hu, Y. L., Guan, L., Kaback, R. H., and Girvin, M. (2002). An approach to membrane protein structure without crystals. Proc Natl Acad Sci U S A, 99(22):14037-40. PMCID: PMC137832

>>Download PDF File

[6] Guan, L., Sahin-Toth, M., and Kaback, H. R. (2002). Changing the lactose permease of Escherichia coli into a galactose-specific symporter. Proc Natl Acad Sci U S A, 99(10):6613-8. PMCID: PMC124451

>>Download PDF File

[5] Guan, L., Murphy, F. D., and Kaback, H. R. (2002). Surface-exposed positions in the transmembrane helices of the lactose permease of Escherichia coli determined by intermolecular thiol cross-linking. Proc Natl Acad Sci U S A, 99(6):3475-80. PMCID: PMC122548

>>Download PDF File

[4] Zhang, W., Guan, L., and Kaback, H. R. (2002). Helices VII and X in the lactose permease of Escherichia coli: proximity and ligand-induced distance changes. J Mol Biol, 315(1):53-62. PMID: 11771965

>>Download PDF File

[3] Guan, L., Weinglass, A. B., and Kaback, H. R. (2001). Helix packing in the lactose permease of Escherichia coli: localization of helix VI. J Mol Biol, 312(1):69-77. 11545586  

>>Download PDF File

[2] Guan, L. and Nakae, T. (2001). Identification of essential charged residues in transmembrane segments of the multidrug transporter MexB of Pseudomonas aeruginosa. J Bacteriol, 183(5):1734-9. PMCID: PMC95059

>> Download PDF File

[1] Guan, L., Ehrmann, M., Yoneyama, H., and Nakae, T. (1999). Membrane topology of the xenobiotic-exporting subunit, MexB, of the MexA,B-OprM extrusion pump in Pseudomonas aeruginosa. J Biol Chem, 4(15):10517-22. PMID: 10187844  >> Download PDF File

.

Book Chapters and Reviews

 

[6] Guan, L. & Kaback, H.R. (2013) Glucose/Sugar Transport in Bacteria. Encyclopedia of Biological Chemistry, 2nd edition, 384-387 (Elsevier Inc.)

[5] Guan, L. & Kaback, H.R. (2012) H+-lactose membrane transport protein, LacY. Encyclopedia of Biophysics, 936-943 (Springer).

[4] Kiraly, O., Guan, L., and Sahin-Toth, M. (2011) Expression of recombinant proteins with uniform N-termini. Heterologous Gen Expression in E. coli. Methods in Molecular Biology, 705 (Chapter 10); 175-194 (Springer Science & Business Media, LLC.) PMID: 21125386

[3] Guan, L. & Kaback, H. R. (2006). Lessons from lactose permease. Annual Review of Biophysics & Biomolecular Structure (35):67-91. PMCID: PMC2802108

[2] Guan, L. & Kaback, H. R. (2004). Glucose/Sugar Transport in Bacteria. Encyclopedia of Biological Chemistry, 2; 204-207 (Elsevier Inc.)

[1] Nakae, T., Guan, L., Yoneyama, H., Germ, M., and Nakajima, A. (2002). The topological localization of the subunit proteins of the three-component RND-efflux pump, MexAB-OprM in Pseudomonas aeruginosa. Proceedings of SPIE (4625):106-117.

Last revised: September 9, 2013
©